The mechanisms of citizen participation in lawmaking can be considered as mechanisms of participatory democracy. These institutions enable citizens to submit proposals or opinions in the process of decision-making by governments, so they must be taken into account, even if not being bound by them, ranking them among the institutions of representative democracy and those of direct democracy. These activities are developed by citizens, individually and especially through representatives of social formations, in order to influence the actions of public authorities. The mechanisms that citizens have at their disposal to take part in the legislature are usually citizensâ initiatives that are presented to the parliaments. However, this article is concerned about other forms of participation in the development of bills when they are being handled by the legislative chambers. These instruments, in Spain, are taken into account by citizens or associations being heard in the legislative committees, initially in some autonomous standing orders and more recently in Statutes of Autonomy. The legislative hearings of citizens or associations are not provided at national level because the standing orders of the Spanish Parliament, the Congress and the Senate, only provide hearings of authorities or experts. This article analyzes these mechanisms and their most recent reforms as ways of opening the legislative process to persons and groups outside the chamber, as an additional form of pluralism